Neonatal Hypoglycemia Following Diet-Controlled and Insulin-Treated Gestational Diabetes Mellitus

OBJECTIVE To assess the risk of neonatal hypoglycemia following diet-controlled and insulin-treated gestational diabetes mellitus (GDM) and how it relates to birth weight. RESEARCH DESIGN AND METHODS Prospective cohort study included term neonates born after GDM from January 2013 through December 2015 at the University Medical Center Utrecht (Utrecht, the Netherlands). Routine screening of neonatal blood glucose levels was performed at 1, 3, 6, 12, and 24 h after birth. Main outcome measures were neonatal hypoglycemia defined as blood glucose £36 mg/dL (severe) and £47 mg/dL (mild). RESULTS A total of 506 neonates were included, born after pregnancies complicated by GDM treated either with insulin (22.5%) or without insulin (77.5%). The incidence of mild and severe hypoglycemia was similar in the insulin-treated and diet-controlled groups (33 vs. 35%, P = 0.66; and 20 vs. 21%, P = 0.79). A birth weight >90th centile was seen in 17.2% of all infants. Although children with a birth weight >90th centile had the highest risk for hypoglycemia, the vast majority of hypoglycemia (78.6%) was detected in those with a birth weight <90th centile. Over 95% of all hypoglycemia occurred within 12 h after birth. CONCLUSIONS Routine screening for neonatal hypoglycemia following pregnancies complicated by GDM reveals high incidence of both mild and severe hypoglycemia for both diet-controlled and insulin-treated GDM and across the full range of birth weight centiles. We propose routine blood glucose screening for neonatal hypoglycemia within the first 12 h of life in all neonates after GDM, irrespective of maternal insulin use or birth weight.